The Templars were the principal crusading order of the Middle Ages. They were the chief pillar of the crusading kingdom of Jerusalem before its final collapse in 1291. They played a heroic role in the defence of its last redoubt, at Acre. Their courage was legendary. Their casualties were high, even by the standards of Middle Eastern warfare: six of the twenty-three grand masters died in battle or as prisoners of war. These were recent memories when, on 13 October 1307, all of the order’s members in France were simultaneously arrested and had their property seized by royal officials, in accordance with secret instructions issued a month earlier by the French king, Philip IV (known as the Fair). It was an exercise of state power that no other government of the period could have matched.

The arrests created a sensation across Europe. The reasons were summarily set out in the warrants that the king’s officials brought with them as they set about their task. Unnamed persons had reported ‘detestable’ crimes committed by the order. A preliminary investigation had revealed that on entry to the order candidates were routinely required to engage in blasphemous rituals: to deny Christ, to spit or trample on the Cross, and to participate in a variety of homoerotic acts. The arrests were the prelude to a series of investigations and trials extending over the next seven years. A large number of Templars, probably the majority, signed written confessions admitting everything. Ultimately, the order was dissolved by Pope Clement V. Several hundred of its members were convicted of heresy by ecclesiastical courts acting under pressure from the king’s ministers. Many of the more prominent among them were burned at the stake, including the grand master, Jacques de Molay. He met his end with impressive courage on an island in the Seine, as the king looked on from the garden of the royal palace.

The condemnation of the French Templars divided opinion at the time and has done so ever since. There are three main schools of thought. The first holds that the Templars were guilty as charged. This was the view taken by 19th-century historians such as Jules Michelet, based on the recent publication of the confessions. Few serious scholars would sign up to this position today. Then there are those who, like Voltaire and the American historian of the Inquisition H C Lea, regarded the whole indictment as a put-up job supported by no evidence worthy of the name. Finally, there is the ‘no smoke without fire’ school, which is currently the most influential. Its adherents are sceptical about the suggestion that the entire order could have been guilty. But they think that a number of its members probably did engage in at least some of the practices alleged against them, even if the details were exaggerated.

Since 2000, Alain Demurger has written three books on the end of the Templars, as well as a number of articles in specialist journals and essay collections. His views have undergone an interesting evolution over the years. He began as a ‘no smoke without fire’ man. Indeed, he once thought that there was probably quite a lot of fire. But reflection and further research have persuaded him of his errors. This book, which appeared in French in 2015, marks his conversion to the case for the defence.

The case for the defence is so strong that it is hard to understand why it was ever seriously doubted. The starting point is the fantastic character of the allegations themselves. If they were true, it meant that the Templars had adopted uniform initiation ceremonies across the whole order, something that would have required a good deal of coordination, presumably at a high level. Yet why should the order, many of whose members had died fighting for the Christian cause in the Holy Land or refused to abjure their faith in Egyptian prisons, have renounced Christ or adopted practices so much at odds not only with its own traditions but also with the ethos of the Christian societies around them? The original source of the allegations was a small number of renegade members with personal grudges, whom even Philip the Fair found hard to believe. It was his ministers Guillaume de Nogaret and Guillaume de Plaisians who gave traction to the prosecution case. They sought out other disaffected Templars. They placed moles inside the order, with a view to finding evidence to match the allegations. Some of them were well rewarded for their pains.

The truth is that the confessions were and are the only basis for believing in the Templars’ guilt. Yet as evidence they are worthless. They were the result of persistent interrogation, based on a preconceived view of what must have happened. The accusations were derived from manuals of interrogation prepared by experienced inquisitors during the previous century. These comprised a catalogue of acts and beliefs of a kind that the inquisitors expected of heretics. The accused were presented with the allegations, followed by a demand for admissions. The tribunals’ procedures were based on civil law, which distrusted witness evidence and insisted on an admission as the only solid basis for conviction. To obtain that admission, the law sanctioned the use of torture. All the Templars who confessed were either tortured or threatened with torture. Hence the formulaic consistency of almost all the surviving confessions. It is true that a tortured suspect had to be given the opportunity to confirm his confession after the torture had ceased. But if he refused, he would simply be returned to the torturers. It is clear that many of them were also told, in spite of its doubtful basis in canon law, that any attempt to withdraw their confessions would be treated as a ‘relapse’ into heresy. Canon law required a ‘relapsed’ heretic to be burned. Even so, a surprisingly large number of Templars insisted that there was no truth in the confessions that had been beaten out of them. They went to the stake asserting their innocence, though they could have saved themselves if they had told their judges what they wanted to hear.

Outside France, where torture was hardly used, there were no confessions. When the king of England, Edward II, was sent the dossier by Philip the Fair and invited to proceed against the Templars of England using the methods that had succeeded in France, he famously replied that he did not believe a word of it and that English law did not countenance torture. The papal inquisitors who visited England to interrogate the Templars there drew a complete blank. In Aragon, torture was used on eight Templars, none of whom confessed. It was not tried again and all the accused were acquitted. In Italy, where the chief commissioner responsible for the prosecution would not allow the use of torture, none of the accused confessed.

It is perfectly possible that, unlike his fellow monarchs, Philip the Fair genuinely believed that the Templars were guilty. He was a man of wooden obstinacy and credulous piety. But it seems most unlikely that his view was shared by his ministers. Their motives must be a matter for speculation. Demurger thinks that they were out to bully the pope, with whom the French government had many bones of contention. To my mind, much the most likely explanation is one that Demurger dismisses out of hand, namely money. The order was extremely rich, not just in land but also in cash, and the king was in serious financial difficulty. This was why it was necessary to press charges against the entire order and not just against individual members. In the end, it did Philip little good. The pope was only willing to dissolve the order on the condition that its assets were transferred to the other crusading order, the Knights Hospitaller of St John of Jerusalem. The crown recovered its expenses, which were considerable, but nothing more.

Alain Demurger has written a fine scholarly narrative of the fall of the Templars, carefully and stylishly dissecting an immense body of evidence. To anyone who has studied the show trials of 1930s Russia or the more extravagant allegations of Satanism and ritual child abuse in modern England, this exercise in prosecutorial psychology will have a depressingly familiar ring. Of course, there are many questions that, barring the discovery of new sources, will never be answered. Some of Demurger’s more adventurous hypotheses may strike readers as rather fanciful. But his central conclusion seems inescapable: the charges against the Templars were a cynical fabrication by ministers of the French government.